Optimization of your Microfit Solar Panel System.

Click to photos/graphs to enlarge viewing:

How to Optimize Your Microfit Solar Panel System

I have written all ready about the optimization features of our 10 kW microfit solar panel system installed by Flexible Solar of Windsor Ontario.  I believe that I highlighted 3 optimization features of our program.  Only one feature remained to be verified. We need to verify that the array will harvest more energy than straight South facing panels.  This will require looking at all results up to and including 21 June.  Initial results show that all is working as designed.

East-West Dynamic Tilting Array:

I designed a two dimensional array located on our East-West facing garage.  This consists of two -4 panel arrays each located on the East and West roof at the peak line.  The purpose was to have for example, the west facing array face east in the AM and the east face west in the PM.  Control is via a PLC and is automatic.

Here is a photo taken looking West to show both arrays in the AM.  Not a good solar day so far.

Here is the array looking from the West to East.  You can see the full extension of the West panels and the optimizers under neath the panels.

We even got some geese taking a look.  The alumimum plate is to stiffen the panel against vibration caused by wind loading.  Safety chains now installed and eliminate wind vibration. I still have yet to install the automatic shutdown when wind exceeds 20 mph.

Initially, during December and January, we were able to harvest about 80% of what a good South facing panel will do.  South facing panels being the best and the standard for comparison.

Here is the results from 19th February.  Total harvesting was 46 kW hours.  Not too bad for a day that was terrible in the AM with scattered clouds in the PM.  You will see two panels not producing well.  One is from a defective panel and the other from a defective optimizer.  These will be replace in a few weeks once we can again access the roof with out any snow or ice on it.

The array is shown as the vertical bunch of 8 panels.  The other is the south facing roof. Notice panel 2.0.20 was better than most south facing panels except  those which harvested 1.14 kW hours.  This is approximately two months from the winter solace on 21 December.  We have harvested approximately 1.4 MW hours and expect to harvest 16-18 MW hours.  That means we have harvested 8.75% of our annual harvesting.

The benefit of have a SolarEdge system with optimizers is evident from looking at the variation of output from each panel.  With a straight string inverter system, all of the south panels would be forced to produce the lowest value achieved by you worst panel.  In our case that would be horrible as one panel is only producing 70% of what it should be.  I bought two spare panels for this reason.  The problem with the optimizer just started I believe in February.  It is covered under warrenty.

In perspective, for approximately 4 months of the year you will produce less than south facing panels on sunny days.  On cloudy days, all panels produce equally.  That means for the peak harvesting months your gain will equal or exceed south facing panels when you harvest 82% of your energy.  Panels 1.0.18 and 20 show little loss from the shading from the array that occurs before 11 AM.

The proof of concept is still on going.  To me it only makes sense to use your panels as much as you can though out the day.

How much the array will harvest over and above normal south facing panels is left to be verified.  I can see before 10 AM that west/east at time harvest 50% more than south facing panels.  We still are no where near the optimum AM/PM angle for the panels to achieve their design output. 

To repeat, I designed the system to be optimized from March 21 to Sept 21.  By having some high functioning East/West facing panels you help to square up you harvesting curve or to maximize harvesting.  Basically, you want to have your inverter output to be as high as possible for as long as possible.

As a side note, it is fun to watch the solar gain increase, some times on a daily basis.  This is because the sun's attitude in the sky is increasing daily.  I can see for the past week that the daily peak is steadily increasing from the previous day's result as long as it is sunny around 1 PM.  I though that this would be much slower.  We suffer from a low roof pitch of 22.5 degrees which will disappear by 21 March though to September. For the month of February, the sun's attitude increases by 9 degrees in the sky.  From December 21 there is a 15.6 degree increase the the sun's attitude. By the end of March this will be 27.7 degree increase from December 21.  In addition, the hours of sunlight are getting much longer.  We even saw a robin at our bird feeders yesterday.

At the start of February, I was forecasting a minimum of 20 kW hrs per day with a maximum of 30kW hours for a cloudy day.  We have been fortunate that even with the two panel problems and some snow issues, we peaked at near 58 kW hours on one day and over the past 10 days only had one day below 31 kW hours.

Accordingly, for March we are now forecasting 30-40 kW hrs minimum with peaks about 60-70 kW hours of harvesting on sunny days.  We just might achieve 800 kW hours for February (28 days).  Possible March harvesting of 1 MW hour or more.

If you are thinking about going solar, then I give my highest recommendations to Flexible Solar Solutions serving Windsor and Southern Ontario.  They will tell you straight up if it is good idea or not.

 Just call:

Steve -519 962 9218